A novel frame phase extraction technique for optical‐fiber digital PPM

The problems of achieving slot synchronization and the proper frame frequency in optical fiber digital PPM were previously studied. Self‐synchronization of the PPM format is completed here by considering the extraction of the frame phase directly from the incoming data. An original novel technique that utilizes naturally occurring sequences has been devised and used to extract the frame phase in optical‐fiber digital PPM. Original results are reported that identify two classes of naturally occurring PPM sequences. An original mathematical model is developed and used to predict the spectral properties of these sequences. A generalization of the analysis and implementation techniques is carried out that results in synchronizers that can cope with large PPM word sizes. The improvement in the spectral discrete components per extra tracked sequence is shown to be 6 dB. Original practical results are given and shown to be in agreement with the theoretical results.